Taper attachment construction



Oct. 20, 1942.

c; A. BlcKEL l 2,299,677

TAPER ATTACHMENT CONSTRUCTION Filed June l0,v 1940 5 Sheets-Sheet l fm. l

c. A. BlKEL 2,299,677 ''APER ATTACHMENT CONSTRUCTION Filed .June 1o. 1940 5 sheets-sneu 2 Oc't. 20, 1942.

C. A. BICKEL TAPER ATTACHMENT CONSTRUCTION Oct. 20, 942.

Filed Jun@ 1o, 1940 -5 sheets-sheet 4 IN VEN TOI? Cl/F F0170 A E/CEZ Oef. 20, V1942; CNA, BlCKEL 2,299,677'

ATTACHMENT GONSTRU n I l I/ 40' v op e 0\J ATTO/717575 Patented Cet. 20, 1942 TAPER ATTACHMENT CONSTRUCTION Clifford A. Bickel, Sidney, Ohio, assigner to The Monarch Machine Tool Co., Sidney, Ohio, a

corporation cf Ohio Application June 10, 1940, Serial N0. 339,684

26 Claims.

This invention relates to turning apparatus and particularly to lathes for turning tapers on artcles simultaneously with longitudinal movement of a turning tool.

An object of this invention is to provide a device which can be used in connection with a lathe whereby a taper on a turned article may be produced simultaneously with longitudinal movement with the carriage of a lathe, and wherein the transverse thrust occasioned by the angular movement of the taper turning apparatus will be assumed by a plurality of anti-friction bearing surfaces positioned between the movable guided surfaces of the taper turning apparatus in order to produce, as near as possible, a frictionless operating device.

A further object of this invention is to provide a taper turning apparatus wherein the movable or slidable portions thereof may have a greater travel than has heretofore been possible without the adjacent movable edges leaving an antifriction bearing surface.

Another object of this invention is to provide a taper turning apparatus wherein a multiplicity of small anti-friction bearing devices are interposed between the movable surfaces of the taper turning apparatus to reduce to a minimum the amount of bearing surface.

Another object of this invention is to provide a taper turning apparatus wherein a slide member is guided in suitable channels in a carriage member, and wherein a plurality of rotary antifriction bearing elements are interposed to reduce operating friction between these members.

A further object of my invention is to provide a taper turning device wherein a multiplicity of anti-friction bearing devices are lineally interconnected to provide a continuous chain of small bearing surfaces which may be interposed between the movable elements of the taper turning device.

Another object of this invention is to provide a construction in a taper turning device wherein anti-friction bearing elements are interposed between the movable members of the device, the structure being such that the thrust imposed upon the bearing surfaces may be directed inwardly or outwardly against the surfaces according to the speciic structural arrangement.

Another object of this invention is to provide a taper turning device wherein a slide member is guided upon a carriage member, and wherein a continuous chain of lineally interconnected rotary bearing elements are interposed between the slide and the carriage and means are provided to tension the chain longitudinally, either vertically with respect to the guide members or angularly therefrom.

Another object of this invention is to provide a taper turning device wherein a slide member is guided upon a carriage member by means of a plurality of interconnected anti-friction bearing elements, and wherein the plurality of bearing elements prevent vertical displacement of l the slide from the carriage.

Further objects and advantages will be apparent from the description and the drawings which follow.

In the drawings:

Figure l is a plan view of a lathe with the taper turning device of my invention attached thereto; Figure 2 is a transverse cross-sectional View of the taper turning device;

Figure 3 is a view similar to Figure 2 showing v another form of bearing mounting for the taper turning device and including the operative interconnection with the cross-slide of the lathe;

Figure 4 is a perspective view partially in crosssection showing a portion of the lathe and the taper turning attachment showing a modified bearing structure and follower shoe arrangement;

Figure 5 is a transverse cross-sectional view of the taper turning device similar to Figure 2 showing a modied arrangement of the bearing structure as disclosed in Figure 4;

Figure 6 is a partial sectional view taken along line 6-5 of Figure 2;

Figure '7 is a cross-sectional view of the guideway portion between the slide and carriage of the taper turning device showing a modified arrangement of the bearing assembly disclosed in Figure 3;

Figure 8 is a cross-sectional view of the guideway portion between the slide and the carriage showing a modied bearing arrangement from that disclosed in Figure 2;

Figure 9 is a partial cross-sectional view taken along line 9-9 of Figure 3 and having certain portions thereof broken away to clarify other portions;

Figure l0 is an enlarged elevational View of one of the lineally interconnected antifriction chains used in Figure 9;

Figure 11 is a further enlarged section taken along line H-II of Figure 10 to show the interconnecting link;

Figure 12 is a partial cross-sectional View taken along line I2-I2 of Figure 2;

Figure 13 is an enlarged elevational view of a General construction used in Figl'n general, the taper turning apparatus of this invention consists of a guideway or swivel which may be adapted by suitable means, for use in combination with a lathe or any other machine tool turning apparatus. This swivel is provided with a follower or shoe which engages a guideway in the swivel in such a manner that movement of the shoe in the guideway, when the guideway is arranged angularly. with respect to the axis of rotation of the turning apparatus, will transmit, through a suitable member, an angular motion with respect to the axis of rotation of the turning machine. As this follower or shoe member moves to and fro in the swivel the motion transmitted through the transmitting member will cause a tool, positioned upon the lathe and interconnected with the transmitting member, to move transversely with respect to a workpiece in the lathe while moving longitudinally, thereby cutting a taper upon the workpiece. In this mannerthe cutting tool follows the same angular position of the swivel.

The swivel is pivotally mounted upon a slide member which is held stationarily with respect to the lathe bed. This slide member is in turn positioned upon a carriage bracket which is mounted upon the carriage member of the lathe. As the carriage member of the lathe moves to and fro along the ways of the lathe bed the carriage bracket will be moved longitudinally with respect to the slide member. Since the follower or shoe is interconnected with the tool positioned upon the carriage of the lathe, and with the carriage bracket of the taper turning device, it will be seen that relative movement between the slide and swivel with respect to the carriage bracket, carriage and shoe will produce the aforementioned taper cutting function of the tool carried upon the lathe carriage.

Since the carriage bracket and slide have relative longitudinal movement parallel with the axis of rotation of the turning machine, it may be seen that when the swivel is positioned angularly with respect to the axis of rotation of the turning machine that considerable transverse thrust will be imposed upon the sliding bearing surfaces between the shoe and swivel and between the slide and carriage bracket. Between these surfaces anti-friction bearing devices have been interposed consisting of a multiplicity of individually positioned, but lineally interconnected rotary bearing members to reduce to a minimum the amount of friction created between the various sliding members. As the angle of the angular displacement of the swivel is increased with respect'to the axis of rotation of the turnmg machine, the transverse thrust increases very rapidly so that it is desirable to reduce to a minimum the bearing surfaces and the ease with which the bearings may be rotated, which improved function may be produced by the novel bearing arrangement of this invention.

According to this invention, the bearing arrangement not only reduces the degree of friction between adjacent slidable surfaces but also permits greater longitudinal movement of the slide with respect to the carriage without advancing the slide beyond a frictionless bearing point.

Lathe construction The apparatus of the present invention consists of a lathe I0 having a bed I2 upon which are positioned longitudinally disposed ways I3.

A lathe carriage I4 is positioned upon the ways i3 and is adapted to be carried to and fro by suitable lathe operating mechanism. The carriage I4 is provided with a vertically disposed apron I5 depending vertically from the carriage I4 at the front side of the lathe. The control devices are mounted upon this apron and consist of a manually operable hand wheel I6 which is adapted to engage the feed rack (not shown) of the lathe in order to move the carriage I4 along the ways I3 of the lathe. A clutch operating lever Il is also mounted upon the apron i5 and is provided for controlling the starting and stopping movement of the carriage I4.

Disposed at one end of the lathe bed I0 is a head stock I8 within which there is provided suitable mechanism for driving a live spindle I9. At the opposite end of the lathe and positioned upon the lathe bed I5] there is disposed a tail stock 2e which may be moved to and fro along the ways Ita of the lathe and is provided with a clamping lever (not shown) for retaining the tail stock in any position along the ways I 3a and clamping the same thereto, to position a workpiece (not shown) between the live spindie I9 and the dead center 22 in the tail stock 20. The levez1 2| locks the spindle and dead center 22 in position in the tail stock.

There is positioned upon the carriage Ill a cross-slide 25. This cross-slide 25 is provided with a dovetail, Figure 4, which Cguides the transverse movement of the cross-slide upon the horizontal way 2l. The cross-slide 25 is adapted to be moved to and fro transversely upon the way 27 by means of a cross-feed screw 28 which is connected by suitable gearing mechanism to the feed rod (not shown) in order to provide a machine driven cross-slide 25. The cross-slide Z5 may be operated manually by means of rotatable arm 25a. A compound tool slide 3!) of conventional structure is mounted upon the crossslide 25. The compound tool slide comprises the usual guide member 3| which is moved relative to the cross-slide by means of the manually operatable and rotatable balance wheel 32. The usual micrometer head 33 for indicating the movement of the cross-slide and compound tool slide is provided upon suitable mountings upon the cross-slide 25. A tool post 34 extends vertically from the compound tool slide and is provided with the usual slot in which a working tool may be positioned. In order to rigidly secure the tool in position within the tool post a tool and tool post clamping means 35 is provided upon the top portion of the tool post 34. This clamping means may be of the usual Cam acting construction for quickly securing the tool and tool post rigidly to the compound tool slide.

The cross-feed screw 28 threadedly engages a cross-feed nut 29 mounted upon the cross-slide 25. The cross-feed nut 29 is secured to the cross-slide 25 by means of the bolts 29u. Rotation of the cross-feed screw 28, either manually or automatically through the lathe driving mechanism, within the cross-feed nut 29 will cause the cross-slide 25 to be reciprocated transversely of the lathe. This cross-feed screw 28 is provided with a conventional sliding telescopic connection with the cross-feed operating means. A particular telescopic arrangement of the crossfeed rod 28 with the lathe driving mechanism, to permit transverse movement of the crossslide 2'5 without rotation of the cross-feed screw 28, is more completely disclosed and described in the patent to C. A. Bickel, No. 2,184,377, issued December 26, 1939. The function and the reason for this telescopic arrangement will be hereinafter described.

Taper cutting device The taper cutting device shown in Figures l, 2 and 4 consists of a carriage bracket 49 in which a slide member 4I is guided by means of antifrictic-n bearing devices hereinafter described. The carriage bracket 49 is secured to the carriage I4, positioned upon the ways I3 of the lathe, by means of the bolts 36. In order to retain the carriage I4 from vertical displacement of the ways I3 there is provided a clamping plate 31 which is screwed to the under side oi the lathe carriage I4 by means of suitable screws 38. This clamping plate 31 extends under the edge of the lathe bed I2 and is in sliding engagement therewith to permit the carriage I4 to slide longitudinally upon the ways I3.

The carriage bracket 40 of the taper turning device is provided with vertically extendingr and longitudinally positioned guideways 42 which are in parallel relationship with respect to each other. These guideways 42 thereby provide a channel shaped recess 43 between said guideways in which the slide 4I is adapted to operate in longitudinally guided relationship with the carriage bracket 40, but is retained from longitudinal movement with respect to the lathe bed I2 by means of an anchor rod 299. This rod 299 is secured to an anchor bracket 29| which is mounted upon the way i3 of the lathe and is rigidly secured in position upon the wav I3 by means of a clamping bolt 292. The clamping bolt 292 extends through and engages a clamping bracket (not shown) positioned below the bottom surface of the way I3 so as to clamp the anchor bracket to the way. This provides the means for retaining the slide stationary with respect to the lathe.

Anti-friction bearing devices 44 and 45 are positioned between each of the adjacent cooperating guiding walls of the carriage bracket 49 and slide 4I. A hardened steel insert 46 is positioned in each of the vertically extending guide-- walls 42 of the carriage bracket 49. These steel inserts 46 have a radial recess 41 in the ways thereof which forms one-half of the race for a rotary bearing element, of which the anti-friction bearing device 44 is composed. Similar steel inserts 49 are positioned within the slide 4I and have radially curved recesses 49 in the faces thereof which form the opposite half of a race for the rotary anti-friction bearing device of which the bearing devices 44 and 45 are composed, said bearing devices being hereinafter more fully described.

A swivel member 59 is positioned upon the upper face of the slide 4I and is pivotally mounted thereto by means of a pin 5I. The swivel 50 is arranged so that it may assume an angular position with respect to the longitudinal movement between the slide 4I and the carriage bracket 49. A follower or shoe 52 is positioned upon the swivel 59 and is guided in its path of travel within the swivel 59 by means of the vertically positioned longitudinally extending guidewalls 53, see Figure l or Figure 4, which extend in parallel relation to each other. The swivel 59 is provided at one end thereof with a gear segment 54 which engages a micrometer adjustment device 55. The micrometer adjustment device 55 is provided with a suitable train of gears to cause minute angular movements of the swivel 59 about the p-ivot 5I in order to accurately position the angular position of the swivel 59 with respect to the axis of rotation of the workpiece (not shown) positioned between the live center I9 and the dead center 22 of the lathe. A manually rotatable knob 5G is provided on the micrometer adjustment device for operating the same and may be provided with a calibration around the circumference thereof to indicate the angular position of the swivel 59 in position upon the slide 4I, thumb nuts 51 are provided at each end of the swivel 59. `These thumb nuts 51 cooperate with a threaded bolt which extends downwardly through the swivel 59 and engages the slots 58 positioned in the top face of the slide 4I and cooperate therewith in order to securely bind the swivel 59 to the slide 4I when the thumb nuts are tightened. A scale sight 59 may be provided on one end of the swivel which may slide over indices for indicating the angle of position of the swivel.

As shown in Figure 2, the swivel 59 is slightly modied from that shown in Figures l and 4, and consists of a longitudinally extending member which is substantially T-shaped in crosssection. The horizontal portion 99 of the T- shaped cross-section member rests upon the upper face of the slide 4I and cooperates with the pivot pin 5I. The upwardly extending vertical leg BI of the T-shaped member provides the longitudinal guideway for the shoe 52. The shoe, as shown in Figure 2, consists of a channel-shaped member having a horizontally positioned wall 62 and vertically depending walls 53 which are arranged parallel with respect to each other. The vertically depending walls 63 of the channel-shaped shoe 52 are positioned adjacent the leg 6I of the T-shaped swivel member 59 and parallel thereto. Anti-friction bearing devices B4, comprising a plurality of rotary bearing elements, are positioned between the adjacent cooperating walls of the T-shaped swivel member 59 and the channel-shaped shoe member 52. The anti-friction bearing devices 64 are mounted upon the horizontal wall 52 of the shoe 52 by means of the pins 65 in such a manner that the bearing elements 54 engage opposite parallel sides of the vertically extending leg 5I of the T-shaped swivel 59 to thereby guide the shoe 52y longitudinally along the swivel 59 when the shoe is moved with respect to the swivel during operation thereof.

The shoe 52 is connected to a draw-bar 19 by means of a bolt 1I. The bolt 1I is securely fastened within the horizontal wall 62 of the shoe 52 and extends upwardly through a hole 12in the draw-bar 19. The upper end of the bolt 1I is threaded, upon which a nut 13 is positioned. Washer ,14 and bushing 15 are provided on opposite sides of the draw-bar 19 so that when the nut 13 is tightened upon the bolt 1| the draw-bar 'lil will be held between the Washer 14 and the bushing 15 thereby pivbtally securing the draw-bar 1|) upon the shoe 52..

The draw-bar 1i) is positioned horizontally above the slide 4| and parallel to the plane of the slide 4|, but transversely to the slide. A guiding bracket 16 extends upwardly from the carriage bracket 40 is an integral extension thereof. A similar guide bracket 11 is positioned opposite the guide bracket 16 'and is secured to the carriage bracket to by means of bolts 18. These guide brackets 16 and 11 are provided with transverse slots 19 and 3@ respectively, in which the draw-bar 1G is positioned. A cover plate 8| is positioned above the draw-bar 1Q and is bolted to the brackets 15 and 11 by means of the bolts 82. This cover plate in cooperation with the slots 19 and 8&3 form a guideway in which the draw-bar 10 may slide transversely with respect to the carriage bracket 4i] and slide 4|.

The draw-bar l@ extends beyond the carriage bracket 4t and into cooperative engagement with the cross-feed screw 28, see Figure 3, of the operating mechanism of the lathe. The end of the cross-feed screw 28 which extends through and beyond the cross-feed nut 29, secured to the cross slide 25, is provided with a reduced diameter portion 8E upon which a bearing 81 is positioned. At the ends of the bearing 81 there are provided thrust bearings 88 and 89 which are adapted to receive the transverse thrust transmitted between the draw-bar 1G and the cross-feed screw 28 during operation of the taper turning device. The bearing 81 and the thrust bearings 'and 89 are retained upon the reduced diameter end portion of the cross-feed rod 28 by nut 96, which is in threaded engagement with the extreme end of the reduced diameter portion 85 of the cross-feed screw 23. A transverse flange 9| is provided upon the bearing 81 and engages the extending portion 92 of the draw-bar 1U. The bolts 93 extend through the draw-bar 10 and the transverse flange 9| of the bearing 81 to rigidly secure the draw-bar 1% to the bearing |31 and thus to the cross-feed screw 23. The transverse movement of the draw-bar 1i) created by relative movement of the various parts of the taper turning device is normally transmitted through the cross-feed screw 28. However, there are times when it is desirable that the draw-bar 16 be directly connected to the cross-slide 25, particularly when cutting extremely accurate tapers.

Under these conditions the draw-bar 10 is directly secured to the cross-slide 25 by means of the bolt 94 and the binding member 95. The bolt 94 threadedly engages the binding member 95 to draw the same tightly against the draw-bar 10 and thus binding the draw-bar to the crossslide 25 whereby the transverse motion of the draw-bar 1B may be transmitted directly to the cross-slide 25.

Antijrictz'on bearings The anti-friction bearing devices positioned between the adjacent walls of the movable members of the taper turning attachment consist of a plurality of individually disposed but lineally interconnected bearing elements. The bearing elements as disclosed in this invention consist of individually hardened steel balls which are interlinks, whereby a continuous chain of bali-bearing members is provided. This continuous chain of bearing members is interposed between the ad jacent parallelly disposed cooperating working surfaces so as to provide a plurality of bearing surfaces having small area, thereby reducing the friction between the elements to a minimum. rlIhe chain of bearing elements is arranged and supported in such a manner that the chain can move longitudinally between the adjacent working surfaces as the surfaces are reciprocated to and fro.

In the form of the chain, as disclosed in Figures 2, 8, 12, 13 and 14, there is provided a plurality of hardened steel balls |69. A narrow cage member encircles the ball circumferentially and is provided with a slight radial curve on the inner face thereof to engage the ball and retain the same within the cage, while at the same time permitting rotary movement of the ball within the cage. The cages ISI of adjacent ball members HES are interconnected with suitable links |62, thereby creating a continuous chain of lineally interconnected rotary bearing elements. As more specifically disclosed in Figures 13 and 14, the interconnecting links M2 are shown as having a square cross-section. The cage iti is provided with an extending portion H33 through which the link |92 may protrude. This extending portion H33 of the cage IUI has a square opening m4 therein through which the square interconnecting link protrudes.

The ends of the links |02 are formed with a head thereon after projecting the same through the cage extensions |03 to retain the link within the opening |05 and thus interconnect adjacent cage members il and their retaining bearing members me. The square opening in the cage extension |03 is slightly larger than the square cross-section of the link |02, whereby a slight amount of axial movement will be permitted one cage with respect to the other without serious misalignment of the adjacent cages.

While the form of the interconnecting link and the manner of attaching the respective ball members adjacent each other is specically disclosed with respect to Figures 13 and 14, yet the manner of securing adjacent ball members is not to be limited thereto. Other methods of attaching the respective ball members into a continuous chain of multiple rotary anti-friction bearing devices are shown in Figures 10, ll and 16, and it is conceivable that many other methods of interconnecting the members could be produced.

Disclosed in Figures 10 and 11, the cage member lili is provided with an extension 05 which is T-shaped. An adjacent cage |06 is provided with a channel-shaped end section |31 and is adapted to cooperate with the T-shaped end secbearing devices can be connected by means of suitable interconnecting 75 tion |l5 of the cage |94 so that a pin |08 extending therebetweerrwill provde a pivot joint between the respective cage members. In Figure 16, another type of hinged pin joint is disclosed at |09 whereby the adjacent ball members are interconnected. This type mits movement of the chain at right angles to the plane of the cage, whereas the form as disclosed in Figure l0 will permit a movement of the chain in the same plane as the cage. These interconnected chains of rotary anti-friction used as independently lineally disposed bearing surfaces, or they may be used as an endless chain of bearing surfaces to permit freedom of movement of the chain with respect to the adjacent bearing faces so of joint, however, perthat a greater movement of individual bearing elements is available due to creepage of the continuous chain between the bearing faces as the faces are moved relative to each other. This creepage of the endlessv chain would increase the life of the bearing members.

While the lineally interconnected rotary bearing elements are shown in this application as being continuous chains of bearing elements, it is conceivable that a single row of bearing elements could be used and suitable means could be provided for controlling the longitudinal movement of the individual chains, and While the preferred form of positions of the bearing elements has been shown as being betweenl the slide and carriage bracket of the taper turning device, it is also conceivable that the same type of bearing could be interposed between adjacent working surfaces of the shoe and swivel.

Incorporation of bearing chains into the device As disclosed in Figures 2 and i2, the anti-friction bearing devices 44 and 45 comprise a plurality of individually disposed but lineally interconnected rotary bearing elements |80. These bearing elements are interconnected by the links |32 in such a manner that a continuous chain of bearing elements is provided. Passages I I and I I6 are provided in the carriage bracket 40 and are disposed in' spaced parallel relation with the guideways 45 and 48 which guide, or form the races for the anti-friction bearing devices 44 and 45, respectively. The passages H5 and H5 are disposed angularly from the vertical with respect to the guideways 4S and 43 for the bearing devices 44 and 45, respectively, whereby, the continuous chains of anti-friction bearing devices 44 and 45, are disposed angularly from the vertical since the chains 44 and 45 extend continuously between the longitudinal guide# ways 45 and 48 and return through the passageways H5 and H6 within the carriage bracket 40.

In order to retain the continuous chains of anti-friction bearing devices 44 and 45 inV their proper positions with respect to the guideways 46 and 43 and the passages H5 and H0, respectively, a pulley H'! is provided adjacent each end of the carriage bracket 40. The pulley ||'I is rotatably `mounted upon a bearing H8 which in turn is suitably secured to the carriage bracket 40. The carriage bracket 43 has an enlarged cavity IIS at each end thereof into which passageway H5 terminates. This enlarged cavity I9 provides an area within which the pulley I I1 may be mounted within the walls of the carriage bracket 40, while at the same time providing sufficient area to permit the chain 45 to be guided over the pulley H1 and be directed toward its entrance of the passageway H6. I-hese pulleys H1 mounted adjacent the ends of the carriage bracket and the passageways H5 and I It, respectively, provide the means for tensioning the chains of antifriction bearing devices 44 and 45 through the guideways 41 and 48 and the passageways I i5 and i6 to prevent undue slack in the chain, and to permit free longitudinal movement of the chain with respect to the adjacent bearing surfaces when the slide 4| and carriage 40 are-moved longitudinally with respect to each other.

These continuous chains of antidriction bearing devices also tend to prevent vertical displacement of the slide 4I from the carriage bracket 40, since the radially curved races provided in the adjacent faces of the inserts 46 and 48 prevent vertical movement of the balls |00 between the adjacent working surfaces in the same manner as would the races of an ordinary ball-bearing type of bearing device prevent displacement of the balls from the races therein. These devices also, for this reason, provide a minimum of frictional resistance between the slide and carriage bracket regardless of whether the thrust upon the bearing chains 44 and 45 is vertical, transverse or angular.

In order to adjust the working clearance between the carriage bracket and slide, and their cooperating bearing chains 44 and 45, one of the inserts 46 in the carriage bracket 40 is provided with a tapered wall |25 which cooperates with a similarly tapered wall of the groove |26 in which the insert is positioned. A threaded screw member |21 threadedly engages a threaded opening |255l in the carriage bracket 4. The screw member |2-'Iv has an enlarged flanged portion upon the lbody thereof which engages the insert or gib 46. In order to adjust the clearances between the adjacent working surfaces of the slide 4|, the carriage bracket 40 and the bearing chains 44 and 45 the threaded member |2'a' is rotated to cause movement of the insert or gib 45 with respect to the tapered wall of the groove |26 in the carriage bracket 4|] so as to cause transverse movement of the cooperating surfaces and take up objectionable clearances.

In Figure 5, I have shown a modiiied arrangement whereby the slidev 4| is prevented from vertical displacement lfrom the carriage bracket 4t. Iny this arrangement the slide 4| is provided with gui'deway inserts or gibs |39 and |3| which are positioned on the lower face of the slide 4| and are adapted to rest in a vertical position upon a continuous chain of anti-friction rotary bearing elements |32 and |33, which in turn rest in a vertical position upon guideway inserts |34 and |35 positioned in slots |35 and |31, respectively, in the carriage bracket 40. The continuous lineallyY interconnected chain of bearing elements |32 and |33 extend between their respective guideway inserts and return through the passageways |38 and IB. In this arrangement the vertical thrust of the slide 4| is taken by the bearing chains |32 and |33. To prevent vertical displacement of the slide 4| from the carriage lbracket 40 an anti-friction bearing member |40 is provided, and comprises a plurality of rotary bearing elements retained by the axially movable race members. This anti-friction bearing device |40 is mounted upon a stud |4| which threadedly engages an extending mounting member |42. The mounting member issecured to the slide 4I by means of the bolt |43. l The anti-friction bearing -device |40 bears in a vertical direction against a horizontally positioned platform member |44 which is fastened to a boss |45, which extends upwardly from the carriage bracket 40, by means of the screw |46. By this construction the continuous chains of lineally interconnected bearing elements |32 and |33 are relieved of the function of preventing vertical displacement of the slide from the carriage bracket during operation of the taper turning device. A modied arrangement of this means for retaining the slide 4| from vertical displacement from the carriage bracket 40 is shown in Figure 4, and wherein the anti-friction bearing member |40 is mounted to the carriage bracket 40 rather than to the slide 4|. This arrangement provides an inverted mechanical arrangement of the bearing elements.

In Figure 3, I have shown another mechanical arrangement for mounting the slide 4| upsitioned within parallelly positioned and longitudinally extending grooves |52 and |53, respectively, in the carriage bracket 45. The slide 4| has the inserts |54 and |55 positioned within 1ongitudinally extending slots |56 and |51 in the opposite parallel walls of the slide 4|. These inserts or gibs |54 and |55 extend beyond the parallel walls of the slide dl and are provided with a substantially V-shaped cross-sectional area |58 and |59, respectively. The V-shaped areas |58 and |59 of the inserts or gibs |54 and |55 are adapted to cooperate with the channel-shaped walls of the inserts |56 and |5|, respectively, whereby a guide means is provided for guiding the longitudinal movement of the slide 4| with respect to the carriage bracket 40.

A pair of chains of anti-friction bearing dee vices are positioned between the adjacent walls of the V-shaped crosssectional area of thegib |54 and the channel walls of the insert |56 and comprise the chain |60 and a chain |6|, each of which consists of a plurality of lineally interconnected rotary bearing elements. A similar set of chains E62 and |53 are positioned between the gib |55 and the insert |5|. A passageway |64 is provided in the carriage bracket 40 to permit continuous return of the chains |60 and I5 while a passageway |65 is provided in the carriage racket i6 for return of the chains |62 and |63. The chains |50 and |6| are tensioned between pulleys positioned adjacent the ends of the carriage bracket and their respective passageways in the bracket in the manner as heretofore described. In this arrangement, however, the pulley is a double track pulley, as shown at |61, see Fig. 9, each chain having its own track upon the pulley to follow.

In Figure 7, there is shown a modified arrangement of the positioning of the bearing chains with respect to the slide and carriage bracket from that disclosed in Figure 3, that is, the positioning of the guiding means between the carriage bracket and the slide have been inverted wherein the slide 4| is provided with a down- I wardly extending projection |10, which extends parallel to an upwardly extending guiding member |12 positioned upon the carriage bracket 40. The arrangement of a double set of bearing chains |62a and |63@ between the gib |55a and the insert |53a, is substantially the same as shown in Figure 3, except that in this arrangement, as shown in Figure 7, the transverse thrust of the slide 4| with respect to the carriage bracket i0 will be inwardly against the carriage bracket 40 rather than outwardly. Figure 8 shows a similar inversion of the bearing arrangement from that disclosed in Figure 2, wherein the carriage bracket d receives the transverse thrust inwardly from the slide 4|.

As heretofore mentioned, the continuous chains of lineally interconnected rotary bearing elements could also be used between the shoe 52 and the swivel 50. An arrangement such as disclosed in Figure 17 can be provided wherein the I,

swivel 55a, is mounted upon the slide lila by the pin a. The swivel 56a, in this arrangement is provided with vertically extending guideway walls |86 and |8|. The shoe 52a is provided with vertically depending guideway walls |82 and |83 which are parallel to and adjacent the guideway walls |86 and |8| of the swivel 56a. A chain |84 of lineally interconnected rotary bearing elements is interposed between the cooperating faces |86 and |62 of the shoe 52a and the swivel 56a. A similar chain E65 of lineally interconnected rotary bearing elements is interposed between the cooperating walls |85 and |83 of the shoe 52a, and the swivel 56a, respectively. An adjusting means comprising a tapered insert |86 may be positioned in the swivel 55a, which is moved by means of a threaded screw |81, said adjustment being similar to that disclosed in Figure 6. The shoe 52a is connected to a drawbar in the same manner as has been described with respect to Figure 2 by means of the pin 1 ia.

Operation The taper turning device of this invention may be connected or disconnected at will in order to permit the use of the lathe, either for turning straight pieces or for cutting tapers upon pieces, without removing the device from the lathe. v

When using the lathe in such a manner as to turn a continuous longitudinal diameter upon a workpiece the bolt 252 in the anchor bracket 25| is loosened in order to permit the anchor bracket to slide longitudinally along the way |3 with the carriage M. The bolt 2|5, which threadedly engages a boss 2| and extends through and in threaded engagement with the cover plate 82, is tightened so that the end of the bolt 2|!) binds upon the draw-bar 15 to prevent transverse movement of the draw-bar with respect to the axis of rotation of a workpiece positioned in the lathe. Since the draw-bar 16 is now secured from transverse movement, and since the draw-bar is secured to the cross-feed screw 28 through means of the bearing 81, the cross-feed screw 28 may be rotated through means of the lathe driving mechanism (not shown) to transversely move the cross-slide 25 with respect to the lathe bed i2. The transverse thrust of the cross-feed screw 23 is taken by the bearings 68 and 89 positioned at the end of the cross-feed screw 28.

When it is desired to cut a longitudinal taper upon a workpiece the bolt 262 of the anchor bracket 28| is tightened to secure the anchor bracket rigidly to the way 13 oi the lathe bed, thereby preventing longitudinal movement of the slide when the carriage hi and carriage bracket are moved longitudinally upon the ways of the lathe bed. The bolt 2|6 is loosened to permit the draw-bar 16 to slide transversely within the guideways provided in the rackets 16 and 11. The swivel 55 is positioned at the proper angle., according to the taper desired to be cut upon the workpiece, and the clamping screws 51 are tightened to retain the swivel 511 in its angular position upon the slide 4 Longitudinal movement of the carriage |l, when driven by the feed rod (not shown) of the lathe, will also cause longitudinal movement of the carriage bracket l0 secured to the carriage |43.

Since the shoe 52 is secured to the draw-bar 16,

which in turn is guided by the brackets 16 and 11 secured to the carriage bracket 116, the shoe 52 will be carried in an angular' direction within the swivel 56 while being moved longitudinally.

As shown in Figure 1, the swivel is set to cut a taper of increasing diameter as the carriage I4 is moved longitudinally to the left upc-n the lathe. Under the conditions for cutting a taper upon a workpiece the cross-feed screw 28 is not connected with the driving mechanism of the lathe,l serving the function only of transmitting transverse motion from the draw-bar 'l0 to the crossslide 25. These circumstances require that the cross-feed screw 28 have a telescopic driving attachment with the lathe driving mechanism to permit the transverse movement of the crossfeed screw without rotation thereof.

While the taper cutting apparatus is functioning as a taper cutting device the anchor bracket 20| will retain the slide 4l from longitudinal movement with respect to the lathe lil. The carriage bracket 40, secured to the carriage I4, will be moved longitudinally upon the lathe bed i2 whereby longitudinal movement between the carriage bracket 40 and the slide il is created. The anti-friction bearings 44 and 45 positioned between the cooperating guideways 46 and 48 between tne carriage b-racket 4D and the carriage 4l assume the friction of the movement between the carriage bracket 40 and the slide 4l. Since the shoe 52 is movingr upon the swivel 50 in an angular direction with respect to the axis of rotation of the workpiece positioned in the lathe, v

considerable transverse thrust Vis transmitted through the shoe 52 and the swivel 5i! to the slide 4 l. This transverse thrust is thereby transmitted by the slide 4l to anti-friction bearing devices provided between the slide 4l and the carriage bracket 4. The continuous chain type of antifriction bearing device, as disclosed in this invention, can move longitudinally between ,the slide 4I and the carriage bracket 40 when the slide and carriage bracket are moved longitudinally with respect to each other whereby a rolling bearing action is accomplished by the rotary bearing elements lili] of the anti-friction bearing devices 44 and 45.

rIhere is also a transverse thrust assumed by the anti-friction bearing device 64 positioned between the shoe 52 and the guideway 6| of the swivel 50. This thrust is the same as that which is assumed between the slide l and the carriage bracket 4t. Since the transverse movement transmitted by the draw-bar I0, created from the movement of the shoe 52; 'to the carriage I4 of the lathe is a directly transmitted pushV or pull upon the cross-slide 25, it is seen that the thrust created between the shoe 52 and the swivel 50 and between the slide 4i and the carriage bracket 4`il increases rapidly as the angle of the swivel `5!) is increased and can become sc great as to prevent the necessary sliding action between the elements of the taper cutting device. that the anti-friction device positioned between the various cooperating guiding members be of a type to reduce this friction to a minimum and permit free movementbetween the moving members of the taperY cutting device in order to transmit an accurate taper cut to the workpiece positioned in the lathe.

The necessity for reducing friction between the various movable members of the taper turning device is essential, not only between the carriage bracket and the slide, but also between the shoe and swivel'. Since the movement of the shoe 52 upon the guideway 5l of the swivel' 5B is the means by which transverse motion is transmitted to the cross-slide of the lathe', it is seen that the f movable surfe ces between the shoe and the swivel will carry just as much friction as the slide and carriage bracket. The accuracy of the taper turning device depends upon absolute free movement of the various elements and, as a result,

It is thus necessary retaining the taper cutting device to a maximum LAii) degree of accuracy. The anti-friction bearings used between the shoe and the swivel havebeen more particularly described with regardv to Figure 17.

While the form of taper cutting device heretofore described is a preferred form, it is toA be understood that other `forms of a taper cutting attachment may be arranged to use the same type of anti-friction bearings heretofore described with respect the preferred form. As an example, the carriage bracket and slide could be reversedin position with respect to movement with regard the lathe, that is, the'carriage bracket rather than being mounted upon the lathe carriage and moving therewith, could be stationarily mounted upon the bed ofthe lathe and the slide, inthis instance, would move with the lathe carriage. In this instancel the carriage bracketl could be mounted upon a dovetail positioned upon the bed of the lathe and could be adjustable longitudinally along the lathe bed and be clamped in any desired position along the bed. The work tool would be mounted in the tool slide of the lathe carriage, and would be connected to the taper attachment swivel by means of the connecting bar, or draw-bar, in the usual manner.

It is to be understood that the use of the lineally interconnected rotary bearing elements is not limited to the particular type of apparatus disclosed in this application, but can be used between any movablesuriaces where friction is to be reduced to a minimum.

While the form and embodiment as disclosed in this application showl a preferred form yet it is desirable that the application be not limited thereby, but shall cover the apparatus falling within the scope of the claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a machine tool, member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a passageway in said carriage bracket, a continuous chain of lineally interconnected anti-friction bearing devices interposed between said carriage bracket and said slide, said chain extending continuously through said passageway and between said carriage bracket and said slide.

2. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a guideway positioned in said carriage bracket, a cooperating guideway positioned in said slide, a passageway in said carriage bracket, said passageway being in spaced parallel relationship with said guideways, a continuous chain of lineally interconnected anti-friction bearing devices interposed between said guideways, said chain extending continuously a carriage bracket, a 'slide through said passageway and between said guideways.

3. Inv a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a passageway in said carriage bracket, a continuous chain of lineally interconnected anti-friction bearing devices interposed between said carriage bracket and said slide, said chain extending continuously through said passageway and between said carriage bracket and said slide, and means positioned adjacent each end of said carriage bracket for tensioning said chain therebetween.

4. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a guideway positioned in said carriage bracket, a cooperating guideway positioned in said slide, a passageway in said carriage bracket, said passageway being in spaced parallel relationship with said guideways and disposed angularly from vertical with respect thereto, a continuous chain of lineally interconnected anti-friction bearing devices interposed between said guideways, said chain extending continuously through said passageway and between said guideways and being disposed in a plane angular from vertical, and means positioned adjacent each end of said carriage bracket for tensioning said chain therebetween, said means being disposed in the same angular plane as said chain.

5. In a machine tool, a carriage bracket, a slide member movable longitudinally with respect to said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, a plurality of lineally interconnected anti-friction bearing devices interposed between said carriage bracket and said slide, said devices providing a multiplicity of longitudinally movable anti-friction bearing surfaces which assume the transverse thrust of said slide when said slide is moved relative to said carriage bracket.

6. In a machine tool, a carriage bracket, a slide member movable longitudinally with respect `to said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, a passageway in said carriage bracket, a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide, said chain extending continuously through said passageway and between said carriage bracket and said slide and providing an evenly distributed multiplicity of longitudinally movable anti-friction bearing surfaces which assume the transverse thrust of said slide when said slide is moved relative to said carriage bracket.

7. In a machine tool, a carriage bracket, a slide member movable longitudinally with respect to said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, a passageway in said carriage bracket, a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide, said chain extending continuously through said passageway and between said carriage bracket and said slide, means positioned adjacent each end of said carriage bracket for tensioning said chain therebetween, said chain being reciprocable over said tensioning means, through said passageway and between said slide and carriage bracket when said last mentioned elements are reciprocated relative to each other.

8. In a machine tool, a carriage bracket having longitudinally disposed parallel guides, a slide member cooperating with said guides, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, and a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage bracket guides and said slide.

9. In a machine tool, a carriage bracket having a longitudinally disposed recess with vertical walls, a slide cooperating with said recess walls and guided thereby in its longitudinal movement, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, and a continuous chain of lineally interconnected rotary bearing elements interposed between a wall of said recess and the cooperating wall of said slide.

l0. In a machine tool, a carriage bracket having a longitudinally disposed recess with vertical walls, a slide cooperating with said recess walls and guided thereby in its longitudinal movement, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, a continuous chain of lineally interconnected rotary bearing elements interposed between a wall of said recess and the cooperating wall of said slide, said chain assuming the transverse thrust of said slide due to relative movement between said slide and said carriage bracket and transmitting said thrust outwardly against the recess wall in said carriage bracket.

1l. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a slide member having a channel shaped recess with vertical walls in the bottom face thereof, said guideways and said channel walls providing means to longitudinally guide said slide upon said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, continuous chains of lineally interconnected rotary bearing elements interposed between said guideways and said recess walls, said chains assuming the transverse thrust of said slide due to relative movement between said slide and said carriage bracket and transmitting said thrust inwardly against the guideways on said carriage bracket.

l2. In a machine tool, a carriage bracket hav-` Vasador? ing upwardly extending longitudinally positioned guideways, a slide member having walls parallel to and adjacent said guideways, said guideways and said walls providing means to longitudinally guide said slide upon said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, continuous chains of lineally interconnected rotary bearing elements interposed between said guideways and said walls, said chains assuming the transverse thrust of said slide due to relative movement between said slide and said carriage bracket and transmitting said thrust inwardly against the guideways on said carriage bracket.

13. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a slide member having walls parallel '7^ to and adjacent said guideways, said guideways and said walls providing means tolongitudinally guide said slide upon said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, continuous chains of lineally interconnected rotary bearing elements interposed between said guideways and said walls, and means for adjusting the position of one of the guiding walls with respect to the remaining walls to accurately adjust the clearances between said walls and said bearing chains.

14. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a slide member having walls parallel to and adjacent said guideways, said guideways and said walls providing means to longitudinally i guide said slide upon said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of 1ongitudinal movement between said members, continuous chains of lineally interconnected rotary bearing elements interposed between said guideways and said walls, and an anti-friction bearing device comprising multiple rotary bearing elements positioned to prevent vertical removal of said slide from said carriage bracket.

15. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a slide member having walls parallel to and adjacent said guideways, said guideways and said walls providing means to longitudinally guide said slide upon said carriage bracket, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, continuous chains interposed between said guideways and said walls, said chains preventing vertical removal of said slide from said carriage bracket,

16. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a substantially channel-shaped recess in said guideways, a slide member having walls parallel to and adjacent said guideways, said walls having substantially V-shaped extensions for extending into and cooperating with the walls of said channel-shaped recesses to provide guideway means for said slide, means carried upon said slide member for transmitting a power Amovement angular to the longitudinal movement between said slide and said carriage bracket simultaneouslyv with occurrence of longitudinal movement between said members, and a continuous chain of lineally interconnected rotary bearing elements interposed between each pair of adjacent parallel walls of said guideway means.

17. In a machine tool, a carriage bracket having upwardly extending longitudinally positioned guideways, a substantially channel-shaped recess in said guideways, a slide member having walls parallel to and adjacent said guideways, said walls having substantially V-shaped extensions for extending into and cooperating with the walls of said channel-shaped recesses to provide guideway means for said slide, means carried upon said slide member for transmitting a power movement angular to the longitudinal movement `between said slide and said carriage bracket simultaneously with occurrence of longitudinal movement between said members, a continuous chain of lineally interconnected rotary bearing elements interposed between each pair of adjacent parallel walls of said guideway means means positioned adjacent each endof said carriage bracket for tensioning said chains therebetween, said means positioning said chains in continuous parallel relationship.

18. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, a guide member pivotally supported upon said slide and adapted to be positioned angularly with respect to movement between said slide and said carriage bracket, a follower engaging said guide, said carriage bracket being adapted to engage a source of power to cause relative movement between said bracket and said slide, means engaging said follower and said carriage bracket through which angular movement of said follower is transmitted, and av plurality of lineally interconnected anti-friction bearing devices interposed between said carriage bracket and said slide.

19. In av machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, a guide member pivotally supported upon said slide and adapted to be positioned angularly with respect to movement between said slide and said carriage bracket, a follower engaging said guide, said carriage bracket being adapted to engage a source of power'to cause relative movement between said bracket and said slide, means engaging said follower and said carriage bracket through which angular movement of said follower is transmitted, and a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide.

20. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, a guide member pivotallysupported upon said slide and adapted to be positioned angularly with respect to movement between said slide and said carriage bracket, a follower engaging said guide, said carriage bracket being adapted to engage a source of power to cause relative movement between said bracket and said slide, means engaging said follower and said carriage bracket through which angular movement of said follower is transmitted, and a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide, a passageway in said carriage bracket, said chain extending continuously through said passageway and between said carriage bracket and said slide, and means positioned adjacent each end of said carriage bracket for tensioning said chain therebetween.

21. In a machine tool, means for rotating a workpiece, a longitudinally movable carriage, a cutting tool associated with said carriage and moved relative to the workpiece by the carriage, a guiding member, a following member engaging said guiding member, means interconnecting said following member with said cutting tool, a carriage bracket, a slide associated with said carriage bracket and longitudinally movable with respect thereto, said guiding member being pivotally mounted upon said slide to permit angular displacement of said guiding member with respect to the axis of rotation of the workpiece, said carriage and said carriage bracket being associated and movement thereof being parallel to the axis of rotation of the workpiece, and a pluthereto, said guiding member being pivotally -f mounted up said slide to permit angular displacement of said guiding member with respect to the axis of rotation of the workpiece, said carriage and said carriage bracket being associated and movement thereof being parallel to the axis of rotation of the workpiece, and a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide to assume the transverse thrust caused by the movement of the follower in the angularly displaced guiding member.

23. In a machine toc-l, means for rotating a workpiece, a longitudinally movable carriage, a cutting tool associated with said carriage and moved relative to the workpiece by the carriage, a guiding member, a following member engaging said guiding member, means interconnecting said following member Vwith said cutting tool, a carriage bracket, a slide associated with said carriage bracket and longitudinally movable with respect thereto, said guiding member being pivotally mounted upon said slide to permit angular displacement of said guiding member with respect to the axis of rotation of the workpiece, said carriage and said carriage bracket being associated and movement thereof being parallel to the axis of rotation of the workpiece, a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide, a passageway in said carriage bracket, said chain extending continuously through said passageway and between said carriage bracket and said slide, and means positioned adjacent each end of said carriage bracket for tensioning said chain therebetween.

24. An anti-friction bearing device comprising a plurality of balls, each ball having a narrow cage around the circumference thereof, square apertures in said cage positioned diametrically opposite each other, a square pin extending through the apertures of adjacent cages and retained in said cage apertures, said pins having a slightly less cross-section than said apertures to permit slight axial rotation of said balls.

25. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a guideway positioned in said carriage bracket, a cooperating guideway positioned in said slide, a plurality of lineally interconnected anti-friction bearing devices interposed between said carriage bracket and said slide, and means to adjust the working clearance between said guideways and said antiefriction bearing devices.

26. In a machine tool, a carriage bracket, a slide member movable with respect to said carriage bracket, means carried upon said slide member for transmitting an angular power movement when said slide and said carriage are moved relative to each other, a continuous chain of lineally interconnected rotary bearing elements interposed between said carriage and said slide, and means to adjust the working clearance between cooperating guide walls of said slide and carriage bracket and said chain.

CLIFFORD A. BICKEL. 

